The above mentioned parent application U.S. Ser. No. 08/246,821 discloses a mobile partition wall of a type within the above described field. The mobile partition wall disclosed in the parent application is very effective for partitioning a room in any desired configuration while achieving good noise insulation and good stability of the wall elements. Furthermore, when the partition wall is not needed, the wall elements may be stored in a very small space by being pushed along the tracks and then stacked closely together in a storage location. However, a vertical gap or space remains between the last wall element of the deployed partition wall and a stationary wall of the room, because the last wall element must be pushed a certain distance against the second-to-last wall element to achieve pneumatic coupling thereto. Thus, special measures or efforts have been required for closing this vertical gap in a satisfactorily sealed and noise insulating manner. It has been found that the ease of closing or sealing the gap could be improved.